1. Field of the Invention
This invention is in the area of cord locks, specifically a cord lock which has a simpler construction than prior art cord locks, and which can be easily manufactured of resilient material in a single piece.
2. Description of the Related Art
Various cord locks are known in the art, perhaps the most prevalent of which are the "barrel" or "plunger" locks shown in U.S. Pat. No. 4,288,891 to Boden; U.S. Pat. No. 5,197,166 to Meier et al.; U.S. Pat. No. 5,666,699 to Takahashi; U.S. Pat. No. 5,671,505 to Anscher; and U.S. Pat. No. 5,778,904 to Elsner. A major disadvantage of these locks is that they are comprised of multiple parts--a plastic plunger, a plastic cavity or barrel, and also usually an separate metal spring. These parts are formed separately and then assembled to make the lock, all of which entails considerable extra expense versus a one-piece design. This greater expense has prevented their use in some instances where having the convenience of a cord lock would be desirable.
A second major type of cord lock seen in the prior art comprises a male slide having serrated gripping teeth, which fits into a female socket through which the cord passes. The cord is pinched between the slide and the socket, and is thereby prevented from moving. Examples of this type of cord lock are shown in U.S. Pat. No. 5,572,770 to Boden; U.S. Pat. No. 5,894,639 to Boden et al.; and U.S. Pat. No. 5,987,712 to Tucker. Like the barrel locks discussed above, these locks are formed of two or more pieces, and so have the disadvantage of extra forming and assembly cost versus a one-piece design. Moreover, the cord cannot be easily threaded through these devices without first removing the slide from the socket and later replacing it, which is a disadvantage when installing the device onto cords. Additionally, this type of cord lock is less intuitive to operate and more difficult for a user to immediately comprehend.
A third type of prior art cord lock is exemplified by U.S. Pat. No. 4,769,874 to Tracy; U.S. Pat. No. 5,713,758 to Goodin et al.; and U.S. Pat. No. 5,791,022 to Bohman. In these locks, a tortuous path locks the cord within the device, and the tortuous path is somehow eliminated or negated to free the cord. Like the slide and socket cord locks discussed above, tortuous path cord locks cannot be quickly and easily installed on the cord, because the cord must first be threaded through a lengthy or tortuous path.
Various other cord locks and tighteners are disclosed in U.S. Pat. No. 4,222,157 to Forman; U.S. Pat. No. 4,639,978 to Boden; U.S. Pat. No. 5,263,528 to Patel; and U.S. Pat. No. 5,440,788 t Boden. These locks are either complex and composed of multiple parts, or they are unintuitive to operate, or they are unsuitable for use as a cord lock for drawstrings and other similar items.
Thus, it can be seen that a cord lock which has the convenience of installation and intuitiveness of use of a barrel lock, yet can be easily manufactured in one piece, would be a significant improvement over the prior art.
Accordingly, several objects and advantages of my invention are:
It provides a highly effective means for controlling the length of a drawstring or similar item.
It can be easily molded or otherwise formed in a single piece.
It can be quickly and easily installed on the cord.
It is intuitive and convenient to use.
It is adaptable to cords of various diameters and lengths, and can also be used to clamp hoses, tubes, filaments, or other elongated elements.
Further objects and advantages of my invention will become apparent from a consideration of the drawings and ensuing description.